This special session aims to bring together observers and modelers to explore how stellar feedback shapes the interstellar medium (ISM) across different scales, from the Milky Way to distant galaxies. We will focus on understanding the role, physical mechanisms, and efficiency of stellar feedback in regulating star formation and driving large-scale galactic processes. This session will help place current and future data into the broader context of galaxy evolution, by bridging resolved observations of star formation with theoretical models.

Massive stars play a fundamental role in shaping the ISM and influencing the evolution of galaxies over cosmic time. Through stellar feedback, they drive large-scale bubbles, disrupt molecular clouds, and, in extreme cases, power massive outflows that impact galaxy-wide properties. These effects occur across a vast range of scales, from individual stars (on parsec scales) to entire galaxies (on kiloparsec scales), making a detailed and quantitative understanding of stellar feedback essential for realistic galaxy simulations (e.g., SILCC-ZOOM, FIRE, IllustrisTNG).

On the observational side, major advancements in integral-field spectroscopic mapping (e.g., MUSE, KCWI, SITELLE, SDSS-V/LVM) and resolved stellar population studies (e.g., JWST, HST, Euclid, SDSS-IV/APOGEE, SDSS-V/MWM) now allow direct measurements of the physical mechanisms and efficiencies of stellar feedback at different scales. These observational breakthroughs provide a unique opportunity to test and refine theoretical models.

In the coming decade, future facilities such as VLT/BlueMUSE, ELT/HARMONI, and WST will further revolutionize our understanding by offering higher-resolution spectroscopic mapping of feedback processes across cosmic time. These advances will allow us to address key questions such as:

• How efficiently does stellar feedback regulate star formation across different environments?
• What are the dominant physical mechanisms driving feedback in star-forming galaxies?
• How do observational constraints compare with predictions from state-of-the-art simulations?

By bringing together both observers and modelers, this session will provide a timely platform to connect Milky Way studies with extragalactic research, interpret upcoming datasets, and refine our theoretical understanding of how stellar feedback governs galaxy evolution.

Programme

Our special session will cover observational and theoretical works aimed at understanding how stellar feedback works at various scales. This full-day session will consist of three blocks on different themes relating to:

• < 50pc scales: individual stellar objects and their surrounding ISM in the Milky Way and nearby galaxies
• < 500pc scales: resolved studies of HII regions, star clusters, superbubbles in nearby galaxies
• ~ kpc scales: redistribution of star formation and development of galactic winds as a result of stellar feedback

Invited speakers

• Kathryn Kreckel (Heidelberg University, Germany)
• Megan Reiter (Rice University, USA)
• Bronwyn Reichardt Chu (Durham University, UK)
• Stefanie Walch-Gassner (Cologne University, Germany)

Scientific organisers

Oleg Egorov (Heidelberg University, Germany), Ashley Barnes (ESO, Germany), Anna McLeod (Durham University, UK)

Contact

Oleg Egorov: oleg.egorov @ uni-heidelberg.de